Drill jig



E. ZOLL DRILL JIG April 13, 1954 Filed July 1, 1952 2 zozz INVENTOR.

Patente d Apr. 13, 1954 DRILL JIG" Earl: Zoll', Chula: Vista, Califc, -,assignorzto Ruhr Aircraftzcorporation, GhulaWista,Calif-., acorn nati naof' el omia Application July 1,1952, SerialfNo. 296312? .6 Claims. 1;.

This invention relates-to adrill jig for the drilling of holes in a -workpiece.

Itis an object of the invention to provide a drill jig which-may be easily and quicklyattached to or detached from aworkpieoe in which a hole or holes are to be drilled.

A further object is to provide-a combination clamp and drill jig in which indexing means is used to insure the clamping of the jig to the workpiece accurately at the desired position where the'holes are required;

Another object is to. provide adjustable means to accommodate the clamping of the -ji g to work'- pieces of a--wide: rangeof thickness.

Further objects will become apparent as the description of the:dri1'I jigproceeds. For a .better understanding of the invention, reference is:

made to theaccompanyingdrawing, in which:

Figure I'isaside view'of a clamp and'. attached drill jig embodying the invention;

-Figure'2 is an end view of thedrill jigshownin Figure 1-;

Figure '3 is a cross section takenthrough line 3 3' of Figure 1 on an enlarged scale; and

Figure 41s a top view showing a portion of the clamp.

The illustrated embodiment of the invention comprises an upper arm I70.- connected 'toalower arm II by pivot pin.l2-..and a1pai1'v of handl'es l3; l4 pivoted together by a pin l5 and connected to the armsby pivot pins 16; M: Each of thepivot pins referred'to may be awrivet' which serves to hold the parts together in assembled relation. The lower arm has a flat gripping surface- .|8. adapted to grip the lower surface of a workpiece illustrated as a strip of sheet metal l9 having a preformed cylindrical hole 20. The purpose of the jig illustrated in the drawing is to locate the drilling of two additional holes in sheet IQ for the purpose of attaching a nut plate of known type (not shown) to the sheet by a pair of rivets entered through the additional holes. When a screw passing through hole 20 is then entered in the nut on such plate and rotated, the nut plate holds the nut in position against rotation.

Surface I8 is recessed at 2| to receive the end of an indexing pin 22 to be described later.

The upper arm I0 is flared out to provide a wide end portion 23 through which holes 24 are drilled and intermediate these is a tapped hole 25 in which a screw thread 26 provided on the sleeve 21 is screwed, the sleeve being locked in place on arm It) by a lock nut 23. Secured, as by welding 29, to the end of sleeve 27 is a plate or jaw 30 having a fiat gripping surface 3| parallel to surface I8 and the axis of pivot l2. Plate 33 is provided with a pair of drilled cylindrical holes -32 adapted to snuglyreceivetwo removable drill bushings 33, 34. Each drill bushing has a reamed cylindrical hole *3 5 whose axis is-in alignment with the axis of a hole 24 when theclamp is closed on the workpiece. At its upper end sleeve 21' is interiorlythreaded to receive a threaded adjusting screw 36, having a slot "31 adapted to receive the end of a screw driver. Screw 36 engages the upper end of a compression spring -38'whoselower end engages'the cylindrical head 39 of pin 22, head'39being slidable along the interior wall of sleeve 21.

In using the jig to drill two holes 40', 41' in sheet IS, the sheet is held between arm H and jaw 30 and the tapered end of indexing pin 22 inserted into hole-20=in thesheet, the tapered end of the pin bearing against the peripheral wall of hole 20 to index'the jig in proper position. Upon theoperator grasping-handles I3, 14 by one hand coming into substantial alignment and also an intermediate-point 42 on handle I3 coming into engagement with arm Whena drill 43 held in the-chuck 44 of'a portable electric drill is then passed through-ahole 24 andinto bushing 33, it is guided by-thebushing to cut the hole 40 at the proper position in sheet l9. The engagement of the drill chuck 44 withupper arm H1 prevents the drill from advancing too far and possibly injuring a portion of the workpiece lying under the The'drill-is then withdrawn and inserted in the other hole 24 and bushing 34 to drill the hole 4|. Upon separating the handles I3, M the gripping surfaces I8 and 3| spread apart and the clamp may be withdrawn from the workpiece. v

To drill holes of larger or small diameter, the bushings 33, 34 are removed and replaced by others of the same outside diameter and having central holes of the proper diameter. To drill a thicker workpiece, locknut 28 is loosened and the assembly including sleeve 21 and jaw 30 rotated to advance the thread 26 further into threaded opening 25 a suificient distance to bring the axes of bushings 33, 34 into alignment with the axes of holes 24 and provide a suitable distance between the gripping surfaces to grip the workpiece when the clamp is closed. Locknut 28 is then tightened to lock the parts in position.

This invention may be embodied in other forms or carried out in other ways without departing from the spirit or essential characteristicsthereof. The present embodiment of the invention is therefore to be considered as in all respects illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Having thus described my invention, what I claim as new and useful and desire to secure by Letters Patent is:

l. A combined clamp and drill jig comprising, in combination: an upper arm having a hole therethrough adapted to freely pass a drill; a lower arm having a flat gripping surface; means pivotally supporting said arms; a support depending from said upper arm and having a flat gripping surface; a drill bushing secured to said support and having a cylindrical drill guiding surface disposed under said hole; and a pair of handles connected to said arms and adapted to be grasped by a hand of the operator, the movement of said handles toward each other causing a workpiece disposed on said lower arm to be firmly gripped by said gripping surfaces and held for cutting at a desired point by a rotary drill advancing along the drill guiding surface.

2. The combination claimed in claim 1; in which the lower end of the drill bushing is substantially in the plane of the gripping surface of said depending support.

3. A combined clamp and drill jig comprising, in combination: an upper arm having a vertical hole therethrough; a vertically adjustable support depending from said arm, said support having an upper end disposed in said hole. and a lower portion terminating in a first gripping surface; means for securing said support at any desired elevation on said arm; a lower arm having a flat gripping surface disposed opposite said first gripping surface; means pivotally supporting said arms; a drill bushing on said support at a distance to one side of said hole and having a vertical drill guiding surface; said upper arm having a portion at a level above the top of the drill bushing arranged to limit the downward movement of the drill and a pair of handles pivotally connected to said arms and adapted to be grasped by the hand of an operator, the movement of said handles toward each tary drill advancing along the drill guiding surface.

4. A combined clamp and drill jig adapted to guide a drill for drilling a hole in a workpiece at a predetermined distance from a cylindrical hole preformed in the workpiece comprising, in combination: an upper arm having a screw threaded hole therein; a sleeve having an upper end in threaded engagement with said screw thread; a jaw secured to said sleeve having a first gripping surface and an opening in alignment with the interior of said sleeve; an indexing plunger slidable in said sleeve and having a lower portion extending through said opening and terminating in a conical end; means for biasing said conical end of said plunger into the preformed hole in the workpiece; a lower arm having a flat gripping surface disposed opposite said first gripping surface; means pivotally supporting said arms; a drill bushing secured to said jaw and having a drill guiding surface spaced from said sleeve; and a pair of handles pivotally connected to said arms and adapted to be grasped by the hand of an operator, the movement of said handles toward each other causing a workpiece disposed between said gripping surfaces to be firmly gripped thereby and held for cutting at a de-' sired point by a rotary drill advancing along the drill guiding surface.

5. A combined clamp and drill jig comprising, in combination: an upper arm having a pair of spaced apart holes therethrough adapted to freely pass a drill; a lower arm having a first gripping surface; means pivotally supporting said arms; a depending support secured to said upper arm between said holes and having a gripping surface disposed opposite said first gripping surface; a pair of drill bushings secured to said support and having parallel cylindrical drill guiding surfaces disposed under said holes; an-

References Cited in the fileof this patent UNITED STATES PATENTS Number Name Date Matter June 10, 1947 

